An ethylene-vinyl alcohol copolymer (hereinafter, sometimes abbreviated as “EVOH”) exhibits excellent barrier properties to a gas such as oxygen and excellent melt moldability. It is, therefore, molded into a film, a bottle or the like, or widely used as various packaging materials. EVOH has lower impact strength due to its high crystallinity, and is, therefore, often used as a laminate with a thermoplastic resin having excellent mechanical properties for compensating for the drawback. In particular, in the field of a blow-molded container or the like, a multilayer structure is extensively employed, which has a layer of resin composition containing EVOH and a layer of polyolefin resin such as polyethylene and polypropylene.
For instance, JP57-32952 A has described a multilayer container produced by multilayer co-extrusion blow molding, which is chemical-resistant and less gas-permeable and in which an EVOH layer is an intermediate layer and the outer and the inner layers are polyolefin layers. However, in the multilayer container, a polyolefin layer as an innermost layer is less resistant to an organic solvent, so that, when a content is an organic solvent or the like, the container may be deteriorated, leading to reduced impact resistance after long-term storage.
Resistance to an organic solvent of a container can be improved by employing an EVOH layer as an innermost layer. However, in a container in which an innermost layer is made of EVOH, a polyolefin layer can be laminated on only one side of the EVOH layer, resulting in insufficient impact resistance, and thus the container may not be used in an application requiring high impact resistance. JP2010-95315 A has thus proposed an agrochemical container having, as an innermost layer, a layer of resin composition containing a polymer having EVOH and polyalkylene ether units. The document has described that the agrochemical container is excellent in impact resistance at a low temperature.